The present invention relates to an integrated system for providing environmental control and power to onboard aircraft systems.
Current aircraft power systems are comprised of several major components such as the engine, the environmental control system, and the thermal management system. Typically, these subsystems are designed relatively independently of one another with power being transferred from one subsystem to another in certain predefined ways.
All manned aircraft have an environmental control system to supply cooled pressurized air to the cabin and/or flight deck. This is typically accomplished by the use of an air cycle machine. FIG. 1 illustrates a typical environmental control system 10 for an aircraft. Depending upon the mission point, bleed air from the engine 12 is removed from either the mid- or high-pressure stages of the high compressor 14. The bleed air is first cooled by ram air in a primary heat exchanger. The bleed air is then further compressed in the compressor section 16 of the air cycle machine. Additional cooling of the bleed air is performed in a secondary heat exchanger 18 again using ram air as the coolant. The bleed air is then expanded to the desired pressure across the turbine section 20 of the air cycle machine. The expansion process produces the necessary work required to drive the compressor 16 via a shaft 22 and significantly drops the temperature of the bleed air. The cooled bleed air exiting the turbine section 20 is mixed with cabin recirculation air to maintain the temperature of the air entering the cabin at a given level.
One of the deficiencies of this type of system is the penalties which it creates with respect to engine losses. The bleed air used for this system could be as much as 5% of the core flow from the engine. Other deficiencies include the weight which is added as a result of having to provide one or more heat exchangers. Still further, the system does not address the issue of providing power to or thermally managing other aircraft components.
Accordingly, it is an object of the present invention to provide an integrated environmental control system for an aircraft.
It is yet another object of the present invention to provide a system as above which provides cooling to other aircraft components besides the cabin and/or flight deck.
It is still another object of the present invention to provide a system as above which provides power to aircraft components.
The foregoing objects are attained by the integrated environmental control system of the present invention.
In accordance with the present invention, the integrated environmental control system for an aircraft having at least one propulsion engine is provided. The integrated environmental control system broadly comprises means for using engine bleed air to provide power to at least one aircraft component and to provide cooling to the flight deck and/or cabin.
Further, in accordance with the present invention, a method for providing environmental control to an aircraft is provided. The method broadly comprises the steps of bleeding air from an engine, delivering the bleed air to an inlet of a turbine, using the turbine to provide power to an aircraft mounted accessory drive, and cooling bleed air exiting the turbine and delivering the cooled bleed air to at least one of a flight deck and a cabin.
Other details of the integrated environmental control system of the present invention, as well as other objects and advantages attendant thereto, are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.